Fix 790.

[lilypond.git] / lily / page-layout-problem.cc

diff --git a/lily/page-layout-problem.cc b/lily/page-layout-problem.cc
index 1aa83d3c0b222a9a05dcc8d0efdea51dccd9b802..5e8d6a70e072f479812ecf81699c69257b44d243 100644 (file)
--- a/lily/page-layout-problem.cc
+++ b/lily/page-layout-problem.cc
@@ -105,7 +105,7 @@ Page_layout_problem::Page_layout_problem (Paper_book *pb, SCM page_scm, SCM syst
          else if (0 == Paper_column::get_rank (sys->get_bound (LEFT)))
            spec = between_scores_system_spacing;
 
-         Spring spring (first ? 0 : 1, 0.0);
+         Spring spring (0, 0);
          Real padding = 0.0;
          alter_spring_from_spacing_spec (spec, &spring);
          read_spacing_spec (spec, &padding, ly_symbol2scm ("padding"));
@@ -117,7 +117,7 @@ Page_layout_problem::Page_layout_problem (Paper_book *pb, SCM page_scm, SCM syst
        {
          SCM spec = first ? top_system_spacing
            : (last_system_was_title ? between_title_spacing : before_title_spacing);
-         Spring spring (first ? 0 : 1, 0.0);
+         Spring spring (0, 0);
          Real padding = 0.0;
          alter_spring_from_spacing_spec (spec, &spring);
          read_spacing_spec (spec, &padding, ly_symbol2scm ("padding"));
@@ -253,6 +253,8 @@ Page_layout_problem::append_prob (Prob *prob, Spring const& spring, Real padding
 {
   Skyline_pair *sky = Skyline_pair::unsmob (prob->get_property ("vertical-skylines"));
   Real minimum_distance = 0;
+  bool tight_spacing = to_boolean (prob->get_property ("tight-spacing"));
+
   if (sky)
     {
       minimum_distance = (*sky)[UP].distance (bottom_skyline_);
@@ -266,10 +268,17 @@ Page_layout_problem::append_prob (Prob *prob, Spring const& spring, Real padding
       bottom_skyline_.clear ();
       bottom_skyline_.set_minimum_height (iv[DOWN]);
     }
-  minimum_distance += padding;
 
   Spring spring_copy = spring;
-  spring_copy.ensure_min_distance (minimum_distance);
+  if (tight_spacing)
+    {
+      spring_copy.set_min_distance (minimum_distance);
+      spring_copy.set_inverse_stretch_strength (0.0);
+      spring_copy.set_distance (0.0);
+    }
+  else
+    spring_copy.ensure_min_distance (minimum_distance + padding);
+
   springs_.push_back (spring_copy);
   elements_.push_back (Element (prob));
 }
@@ -386,14 +395,13 @@ Page_layout_problem::find_system_offsets ()
                  if (loose_lines.empty ())
                    loose_lines.push_back (last_spaceable_line);
 
-                 loose_lines.push_back (staff);
                  if (staff_idx)
                    loose_line_min_distances.push_back (min_offsets[staff_idx-1] - min_offsets[staff_idx]);
                  else
                    {
                      Real min_dist = 0;
-                     if (last_spaceable_line)
-                       min_dist = Axis_group_interface::minimum_distance (last_spaceable_line,
+                     if (loose_lines.back ())
+                       min_dist = Axis_group_interface::minimum_distance (loose_lines.back (),
                                                                           staff,
                                                                           Y_AXIS);
                      else // distance to the top margin
@@ -401,6 +409,7 @@ Page_layout_problem::find_system_offsets ()
 
                      loose_line_min_distances.push_back (min_dist);
                    }
+                 loose_lines.push_back (staff);
                }
            }
 
@@ -446,19 +455,6 @@ Page_layout_problem::distribute_loose_lines (vector<Grob*> const &loose_lines,
       Spring spring (1.0, 0.0);
       alter_spring_from_spacing_spec (spec, &spring);
       spring.ensure_min_distance (min_distances[i]);
-
-      if ((spec == SCM_BOOL_F && loose_lines[0] && loose_lines.back ())
-         || !loose_lines[i]
-         || !loose_lines[i+1])
-       {
-         // Insert a very flexible spring, so it doesn't have much effect.
-         // TODO: set a default distance and a compress strength so that a
-         // lyrics line, for example, will stay closer to the top staff
-         // even in a compressed configuration.
-         spring.set_inverse_stretch_strength (100000);
-         spring.set_inverse_compress_strength (100000);
-       }
-
       spacer.add_spring (spring);
     }
 
@@ -608,14 +604,33 @@ Page_layout_problem::read_spacing_spec (SCM spec, Real* dest, SCM sym)
   return false;
 }
 
-// Returns the spacing spec connecting BEFORE to AFTER.  A return
-// value of SCM_BOOL_F means that there should be no spring (in
-// practice, this means that we use a very flexible spring).
+static SCM
+add_stretchability (SCM alist, Real stretch)
+{
+  if (!scm_is_pair (scm_sloppy_assq (ly_symbol2scm ("stretchability"), alist)))
+    return scm_acons (ly_symbol2scm ("stretchability"), scm_from_double (stretch), alist);
+
+  return alist;
+}
+
+// We want to put a large stretch between a non-spaceable line and its
+// non-affinity staff. We want to put an even larger stretch between
+// a non-spaceable line and the top/bottom of the page. That way,
+// a spacing-affinity UP line at the bottom of the page will still be
+// placed close to its staff.
+const double LARGE_STRETCH = 10e5;
+const double HUGE_STRETCH = 10e7;
+
+// Returns the spacing spec connecting BEFORE to AFTER.
 SCM
 Page_layout_problem::get_spacing_spec (Grob *before, Grob *after)
 {
+  // If there are no spacing wishes, return a very flexible spring.
+  // This will occur, for example, if there are lyrics at the bottom of
+  // the page, in which case we don't want the spring from the lyrics to
+  // the bottom of the page to have much effect.
   if (!before || !after)
-    return SCM_BOOL_F;
+    return add_stretchability (SCM_EOL, HUGE_STRETCH);
 
   if (is_spaceable (before))
     {
@@ -624,7 +639,9 @@ Page_layout_problem::get_spacing_spec (Grob *before, Grob *after)
       else
        {
          Direction affinity = to_dir (after->get_property ("staff-affinity"));
-         return (affinity == DOWN) ? SCM_BOOL_F : after->get_property ("inter-staff-spacing");
+         return (affinity == DOWN)
+           ? add_stretchability (after->get_property ("non-affinity-spacing"), LARGE_STRETCH)
+           : after->get_property ("inter-staff-spacing");
        }
     }
   else
@@ -632,7 +649,9 @@ Page_layout_problem::get_spacing_spec (Grob *before, Grob *after)
       if (is_spaceable (after))
        {
          Direction affinity = to_dir (before->get_property ("staff-affinity"));
-         return (affinity == UP) ? SCM_BOOL_F : before->get_property ("inter-staff-spacing");
+         return (affinity == UP)
+           ? add_stretchability (before->get_property ("non-affinity-spacing"), LARGE_STRETCH)
+           : before->get_property ("inter-staff-spacing");
        }
       else
        {
@@ -647,8 +666,11 @@ Page_layout_problem::get_spacing_spec (Grob *before, Grob *after)
            return before->get_property ("inter-loose-line-spacing");
          else if (after_affinity != DOWN)
            return before->get_property ("inter-loose-line-spacing");
+         return add_stretchability (before->get_property ("non-affinity-spacing"), LARGE_STRETCH);
        }
     }
+
+  assert (0);
   return SCM_BOOL_F;
 }